Add script for cherry-picking commits from typeshed (python#11737)

misc/cherry-pick-typeshed.py

@@ -0,0 +1,67 @@
+"""Cherry-pick a commit from typeshed.
+
+Usage:
+
+  python3 misc/cherry-pick-typeshed.py --typeshed-dir dir hash
+"""
+
+import argparse
+import os.path
+import re
+import subprocess
+import sys
+import tempfile
+
+
+def parse_commit_title(diff: str) -> str:
+    m = re.search("\n    ([^ ].*)", diff)
+    assert m is not None, "Could not parse diff"
+    return m.group(1)
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        "--typeshed-dir", help="location of typeshed", metavar="dir", required=True
+    )
+    parser.add_argument(
+        "commit", help="typeshed commit hash to cherry-pick"
+    )
+    args = parser.parse_args()
+    typeshed_dir = args.typeshed_dir
+    commit = args.commit
+
+    if not os.path.isdir(typeshed_dir):
+        sys.exit(f"error: {typeshed_dir} does not exist")
+    if not re.match("[0-9a-fA-F]+$", commit):
+        sys.exit(f"error: Invalid commit {commit!r}")
+
+    if not os.path.exists("mypy") or not os.path.exists("mypyc"):
+        sys.exit(f"error: This script must be run at the mypy repository root directory")
+
+    with tempfile.TemporaryDirectory() as d:
+        diff_file = os.path.join(d, "diff")
+        out = subprocess.run(["git", "show", commit],
+                             capture_output=True,
+                             text=True,
+                             check=True,
+                             cwd=typeshed_dir)
+        with open(diff_file, "w") as f:
+            f.write(out.stdout)
+        subprocess.run(["git",
+                        "apply",
+                        "--index",
+                        "--directory=mypy/typeshed",
+                        "--exclude=**/tests/**",
+                        diff_file],
+                       check=True)
+
+        title = parse_commit_title(out.stdout)
+        subprocess.run(["git", "commit", "-m", f"Typeshed cherry-pick: {title}"], check=True)
+
+    print()
+    print(f"Cherry-picked commit {commit} from {typeshed_dir}")
+
+
+if __name__ == '__main__':
+    main()